Compound and light emitting device including the same

ABSTRACT

A trimetallic complex and a light-emitting device including the same are provided. The trimetallic complex is represented by Formula 1:

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to and benefits of Korean PatentApplication No. 10-2019-0153547 under 35 U.S.C. § 119, filed on Nov. 26,2019, in the Korean Intellectual Property Office, the entire contents ofwhich are incorporated herein by reference.

BACKGROUND 1. Technical Field

Embodiments relate to a compound and a light-emitting device includingthe same.

2. Description of the Related Art

Organic light-emitting devices are self-emission devices that have wideviewing angles, high contrast ratios, short response times, andexcellent characteristics in terms of brightness, driving voltage, andresponse speed, compared to devices in the art.

An organic light-emitting device may include a first electrode disposedon a substrate, and a hole transport region, an emission layer, anelectron transport region, and a second electrode, which aresequentially disposed on the first electrode. Holes provided from thefirst electrode may move toward the emission layer through the holetransport region, and electrons provided from the second electrode maymove toward the emission layer through the electron transport region.Carriers, such as holes and electrons, recombine in the emission layerto produce excitons. These excitons transit from an excited state to aground state, thereby generating light.

SUMMARY

Embodiments include a novel luminescent material and a device includingthe same.

Additional embodiments will be set forth in part in the descriptionwhich follows and, in part, will be apparent from the description, ormay be learned by practice of the embodiments of the disclosure.

In an embodiment, a trimetallic complex is represented by Formula 1.

In Formula 1,

M₁, M₂, and M₃ may be transition metals,

A₁ to A₆ and B₁ to B₆ may each independently be selected from a C₅-C₆₀carbocyclic group and a C₁-C₆₀ heterocyclic group,

Y₁ to Y₂₆ may each independently be C or N,

X₁₁ to X₁₆ and X₂₁ to X₂₆ may each independently be C or N,

L may be selected from a single bond, *—O—*′, *—S—*′, *—C(R₂₁)(R₂₂)—*′,*—C(R₂₁)═*′, *═C(R₂₁)—*′, *—C(R₂₁)═C(R₂₂)—*′, *—C(═O)—*′, *—C(═S)—*′,*—C≡C—*′, *—B(R₂₁)—*′, *—N(R₂₁)—*′, *—P(R₂₁)*—Si(R₂₁)(R₂₂)—*′,*—P(R₂₁)(R₂₂)—*′, and *—Ge(R₂₁)(R₂₂)—*′,

R₁ to R₁₂, R₂₁, and R₂₂ may each independently be selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, asubstituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂),—B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and—P(═S)(Q₁)(Q₂),

two adjacent substituents selected from the group consisting of R₁ toR₁₂, R₂₁, and R₂₂ may optionally be linked to each other to form asubstituted or unsubstituted C₅-C₆₀ carbocyclic group or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group,

a1 to a12 may each independently be an integer from 1 to 4,

* and *′ each indicate a binding site to a neighboring atom, and

at least one substituent of the substituted C₅-C₆₀ carbocyclic group,the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₃₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₁-C₆₀ heteroaryl group, the substituted monovalentnon-aromatic condensed polycyclic group, and the substituted monovalentnon-aromatic condensed heteropolycyclic group is selected from

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₃₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₃₀ alkynyl group, and aC₁-C₃₀ alkoxy group,

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),—S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂),

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group,

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂), and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may eachindependently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensedpolycyclic group, a monovalent non-aromatic condensed heteropolycyclicgroup, a biphenyl group, and a terphenyl group.

In an embodiment, a light-emitting device may include a first electrode,a second electrode facing the first electrode, and a middle layerdisposed between the first electrode and the second electrode andincluding an emission layer, wherein the middle layer includes thetrimetallic complex.

In an embodiment, in the light emitting device, the first electrode maybe an anode, the second electrode may be a cathode, and the middle layermay comprise a hole transport region disposed between the firstelectrode and the emission layer and an electron transport regiondisposed between the emission layer and the second electrode. The holetransport region may comprise at least one selected from the groupconsisting of a hole injection layer, a hole transport layer, anemission auxiliary layer, and an electron blocking layer. The electrontransport region may comprise at least one selected from the groupconsisting of a hole blocking layer, an electron transport layer, and anelectron injection layer.

In an embodiment, an electronic apparatus may comprise a thin-filmtransistor, and the light-emitting device, wherein the thin-filmtransistor includes a source electrode, a drain electrode, an activationlayer, and a gate electrode. The first electrode of the light-emittingdevice may be electrically connected to at least one of the sourceelectrode and the drain electrode of the thin-film transistor.

BRIEF DESCRIPTION OF THE DRAWING

The above and other aspects, features, and advantages of embodiments ofthe disclosure will be more apparent from the following descriptiontaken in conjunction with the FIGURE, which shows a schematiccross-sectional view of a structure of a light-emitting device accordingto an embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawing. In this regard, theembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are described below, by referring to the FIGURE, to explainaspects of the invention.

Like reference numerals refer to like elements throughout. In thedrawing, the dimensions of structures are exaggerated for clarity ofillustration. It will be understood that, although the terms first,second, etc. may be used herein to describe various elements, theseelements should not be limited by these terms. These terms are only usedto distinguish one element from another element. Thus, a first elementcould be termed a second element without departing from the teachings ofthe invention. Similarly, a second element could be termed a firstelement. As used herein, the singular forms are intended to include theplural forms as well, unless the context clearly indicates otherwise.

As used herein, the term “and/or” includes any and all combinations ofone or more of the associated listed items for the purpose of itsmeaning and interpretation. For example, “A and/or B” may be understoodto mean “A, B, or A and B.” The terms “and” and “or” may be used in theconjunctive or disjunctive sense and may be understood to be equivalentto “and/or”. Throughout the disclosure, the expression “at least one ofa, b or c” indicates only a, only b, only c, both a and b, both a and c,both b and c, all of a, b, and c, or variations thereof.

The phrase “at least one of” is intended to include the meaning of “atleast one selected from the group of” for the purpose of its meaning andinterpretation. For example, “at least one of A and B” may be understoodto mean “A, B, or A and B.” When preceding a list of elements, the term,“at least one of,” modifies the entire list of elements and does notmodify the individual elements of the list.

It will be further understood that the terms “comprises,” “comprising,”“includes,” and/or “including,” when used in this specification, specifythe presence of stated features, numerals, steps, operations, elements,parts, or the combination thereof, but do not preclude the presence oraddition of one or more other features, numerals, steps, operations,elements, parts, or the combination thereof.

It will be further understood that when a layer, a film, a region, aplate, etc. is referred to as being “on” or “above” another part, it canbe “directly on” the other part, or intervening layers may also bepresent. It will also be understood that when a layer, a film, a region,a plate, etc. is referred to as being “under” or “below” another part,it can be “directly under” the other part, or intervening layers mayalso be present. When an element is referred to as being disposed “on”another element, it can be disposed under the other element.

The spatially relative terms “below”, “beneath”, “lower”, “above”,“upper”, or the like, may be used herein for ease of description todescribe the relations between one element or component and anotherelement or component as illustrated in the drawings. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation, in addition tothe orientation depicted in the drawings. For example, in the case wherea device illustrated in the drawing is turned over, the devicepositioned “below” or “beneath” another device may be placed “above”another device. Accordingly, the illustrative term “below” may includeboth the lower and upper positions. The device may also be oriented inother directions and thus the spatially relative terms may beinterpreted differently depending on the orientations.

Unless otherwise defined, all terms used herein (including technical andscientific terms) have the same meaning as commonly understood by thoseskilled in the art to which this disclosure pertains. It will be furtherunderstood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an ideal or excessively formal sense unlessclearly defined in the specification.

In one embodiment, a trimetallic complex is represented by Formula 1.

In Formula 1,

M₁, M₂, and M₃ may be transition metals,

A₁ to A₆ and B₁ to B₆ may each independently be selected from a C₅-C₆₀carbocyclic group and a C₁-C₆₀ heterocyclic group,

Y₁ to Y₂₆ may each independently be C or N,

X₁₁ to X₁₆ and X₂₁ to X₂₆ may each independently be C or N,

L may be selected from a single bond, *—O—*′, *—S—*′, *—C(R₂₁)(R₂₂)—*′,*—C(R₂₁)═*′, *═C(R₂₁)—*′, *—C(R₂₁)═C(R₂₂)—*′, *—C(═O)—*′, *—C(═S)—*′,*—C≡C—*′, *—B(R₂₁)—*′, *—N(R₂₁)—*′, *—P(R₂₁*—Si(R₂₁)(R₂₂)—*′,*—P(R₂₁)(R₂₂)—*′, and *—Ge(R₂₁)(R₂₂)—*′,

R₁ to R₁₂, R₂₁, and R₂₂ may each independently be selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, asubstituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂),—P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and—P(═S)(Q₁)(Q₂),

two adjacent substituents of R₁ to R₁₂, R₂₁, and R₂₂ may optionally belinked to each other to form a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup,

a1 to a12 may each independently be an integer from 1 to 4,

* and *′ each indicate a binding site to a neighboring atom, and

at least one substituent of the substituted C₅-C₆₀ carbocyclic group,the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₃₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₁-C₆₀ heteroaryl group, the substituted monovalentnon-aromatic condensed polycyclic group, and the substituted monovalentnon-aromatic condensed heteropolycyclic group is selected from:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₃₀alkyl group, a C₂-C₃₀ alkenyl group, a C₂-C₃₀ alkynyl group, and aC₁-C₃₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),—S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃-1 to Q₃₃ may eachindependently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₃₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensedpolycyclic group, a monovalent non-aromatic condensed heteropolycyclicgroup, a biphenyl group, and a terphenyl group.

When a1 to a12 are integers of 2 or more, the substituents R₁ to R₁₂ maybe identical to or different from each other. For example, when a1 is aninteger of 2 or more, the substituents R₁(s) may be different from oridentical to each other. For example, when a2 is an integer of 2 ormore, the substituents R₂(s) may be different from or identical to eachother. The same applies to other substituents R₃ to R₁₂.

For example, adjacent R₁(s) may be linked together to form a substitutedor unsubstituted C₅-C₆₀ carbocyclic group or a substituted orunsubstituted C₁-C₆₀ heterocyclic group. For example, adjacent R₂(s) maybe linked together to form a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup. The same applies to other substituents R₃ to R₁₂.

The trimetallic complex of Formula 1 according to an embodiment may notonly improve stability by making a structure of ligands that are linkedto each other more rigidly, but may also further tilt an angle betweenthe ligands based on a central metal to inhibit formation of an excimer.As a result, a light-emitting device including the trimetallic complexof Formula 1 according to an embodiment may have improved efficiency andlifespan.

In one embodiment, M₁, M₂, and M₃ may each independently be selectedfrom platinum (Pt), palladium (Pd), copper (Cu), silver (Ag), gold (Au),rhodium (Rh), iridium (Ir), ruthenium (Ru), and osmium (Os). M₁, M₂, andM₃ may be identical to or different from one another.

For example, M₁ may be selected from platinum (Pt), palladium (Pd), andosmium (Os).

In one embodiment, M₂ and M₃ may each be a metal different from M₁. Forexample, M₂ and M₃ may be identical to or different from each other andmay each be a metal different from M₁.

In one embodiment, M₂ and M₃ may each independently be selected fromrhodium (Rh), iridium (Ir), and ruthenium (Ru).

For example, M₂ and M₃ may each be rhodium (Rh) and iridium (Ir). Forexample, each of M₂ and M₃ may be rhodium (Rh). For example, each of M₂and M₃ may be iridium (Ir). For example, M₂ and M₃ may each be rhodium(Rh) and ruthenium (Ru). For example, each of M₂ and M₃ may be ruthenium(Ru). For example, M₂ and M₃ may each be iridium (Ir) and ruthenium(Ru).

In one embodiment, A₁ to A₆ and B₁ to B₆ may each independently beselected from a benzene group, a naphthalene group, an anthracene group,a phenanthrene group, an azulene group, a triphenylene group, a pyrenegroup, a chrysene group, a cyclopentadiene group, a1,2,3,4-tetrahydronaphthalene group, a furan group, a thiophene group, asilole group, an indene group, a fluorene group, an indole group, acarbazole group, a benzofuran group, a dibenzofuran group, abenzothiophene group, a dibenzothiophene group, a benzosilole group, adibenzosilole group, an indenopyridine group, an indolopyridine group, abenzofuropyridine group, a benzothienopyridine group, abenzosilolopyridine group, an indenopyrimidine group, anindolopyrimidine group, a benzofuropyrimidine group, abenzothienopyrimidine group, a benzosilolopyrimidine group, adihydropyridine group, a pyridine group, a pyrimidine group, a pyrazinegroup, a pyridazine group, a triazine group, a quinoline group, anisoquinoline group, a quinoxaline group, a quinazoline group, aphenanthroline group, a pyrrole group, a pyrazole group, an imidazolegroup, a 2,3-dihydroimidazole group, a triazole group, a2,3-dihydrotriazole group, an oxazole group, an isooxazole group, athiazole group, an isothiazole group, an oxadiazole group, a thiadiazolegroup, a benzopyrazole group, a pyrazolopyridine group, a furopyrazolegroup, a thienopyrazole group, a benzimidazole group, a2,3-dihydrobenzimidazole group, an imidazopyridine group, a2,3-dihydroimidazopyridine group, a furo imidazole group, athienoimidazole group, an imidazopyrimidine group, a2,3-dihydroimidazopyrimidine group, an imidazopyrazine group, a2,3-dihydroimidazopyrazine group, a benzoxazole group, a benzothiazolegroup, a benzoxadiazole group, a benzothiadiazole group, a5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinolinegroup.

In one embodiment, Y₄, Y₉, Y₁₀, Y₁₅, Y₂₀, Y₂₁, Y₂₄, and Y₂₅ may each beN.

For example, Y₄, Y₉, Y₁₀, Y₁₅, Y₂₀, Y₂₁, Y₂₄, and Y₂₅ may each be N, andY₁ to Y₃, Y₅ to Y₈, Y₁₁ to Y₁₄, Y₁₆ to Y₁₉, Y₂₂, and Y₂₃ and Y₂₆ mayeach be C.

In one embodiment, X₁₁ to X₁₆ and X₂₁ to X₂₆ may each be C.

In one embodiment, L may be *—O—*′, and Y₁, Y₇, Y₈, Y₁₁, Y₁₂, Y₁₈, Y₁₉,Y₂₂, Y₂₃, Y₂₆, X₁₁, X₁₄, X₂₁, and X₂₄ may each be C.

In one embodiment, A₁ to A₆ and B₁ to B₆ may each independently beselected from a C₅-C₆ carbocyclic group and a C₃-C₇ heterocyclic group.

The carbocyclic group and the heterocyclic group are understood byreferring to the definition of the substituent used herein. The term“C₅-C₆ carbocyclic group” refers to a carbocyclic group having 5 to 6carbon atoms. The term “C₃-C₇ heterocyclic group” refers to aheterocyclic group having 3 to 7 carbon atoms.

In one embodiment, A₁ to A₆ may each independently be a C₅ heterocyclicgroup. The “C₅ heterocyclic group” refers to a heterocyclic group having5 carbon atoms.

In one embodiment, B₁ to B₆ may each independently be a C₃-C₇heterocyclic group.

In one embodiment, A₁ to A₆ may each independently be a 6-membered ringincluding one or more N(s).

In one embodiment, B₁ to B₆ may each independently be a 5-membered ringincluding two or more N(s). For example, B₁ to B₆ may each independentlyinclude two N(s). For example, B₁ to B₆ may each independently includethree N(s).

In one embodiment, A₁ to A₆ and B₁ to B₆ may each independently beselected from a benzene group, a pyridine group, an imidazole group, a2,3-dihydroimidazole group, an imidazopyrimidine group, and abenzimidazole group.

For example, A₁ to A₆ may each independently be selected from a benzenegroup and a pyridine group. For example, B₁ to B₆ may each independentlybe selected from an imidazole group, a 2,3-dihydroimidazole group, animidazopyrimidine group, and a benzimidazole group.

In one embodiment, Formula 1 may be represented by Formula 2 below:

In Formula 2, definitions of R₃₁ to R₃₆ are the same as the definitionof R1 of Formula 1, and X31 to X34 may each independently indicate C orN. M1, M2, M3, L, R1 to R12, and a1 to a12 are the same as described inconnection with Formula 1.

In Formula 2, a dashed line indicates a conjugated state.

In a bond between a metal and a ligand in Formula 2, when a binding siteof the ligand is N, a bond between the metal and N may be a coordinatebond. The same applies to Formula 1.

In one embodiment, in Formula 2, L may be *—O—*′, R₁ to R₁₂ may eachindependently be —F, —Cl, —Br, or —I, and R₃₁ to R₃₆ may eachindependently be a substituted or unsubstituted C₁-C₆₀ alkyl group.

In one embodiment, the trimetallic complex represented by Formula 1 maybe one of the following compounds:

The expression “(a middle layer) includes at least one compound” as usedherein may include an embodiment in which a middle layer (or asubcomponent thereof) includes identical compounds represented byFormula 1 and an embodiment in which an organic layer (or a subcomponentthereof) includes two or more different compounds represented by Formula1.

For example, the middle layer may include, as the compound, onlyCompound 1. In this regard, Compound 1 may exist only in the emissionlayer of the light-emitting device. In embodiments, the middle layer mayinclude, as the compound, Compound 1 and Compound 2. In this regard,Compound 1 and Compound 2 may exist in an identical layer (for example,Compound 1 and Compound 2 may all exist in an emission layer), ordifferent layers (for example, Compound 1 may exist in an emission layerand Compound 2 may exist in an electron transport region).

According to one embodiment, a light-emitting device may include:

a first electrode;

a second electrode facing the first electrode; and

a middle layer disposed between the first electrode and the secondelectrode and including an emission layer,

wherein the middle layer includes the compound of Formula 1. Forexample, the light-emitting device may be an organic light-emittingdevice.

According to one embodiment,

the first electrode of the light-emitting device may be an anode,

the second electrode of the light-emitting device may be a cathode, and

the middle layer may further comprise a hole transport region disposedbetween the first electrode and the emission layer and an electrontransport region disposed between the emission layer and the secondelectrode.

The hole transport region may include at least one selected from thegroup consisting of a hole injection layer, a hole transport layer, anemission auxiliary layer, and an electron blocking layer.

The electron transport region may include at least one selected from thegroup consisting of a hole blocking layer, an electron transport layer,and an electron injection layer.

In one embodiment, the emission layer may be a phosphorescent emissionlayer.

In one embodiment, the trimetallic complex of Formula 1 may be includedin the emission layer.

In one embodiment, the emission layer may include a dopant, and thedopant may include the compound. For example, the dopant may include thetrimetallic complex of Formula 1.

In one embodiment, the trimetallic complex of Formula 1 may act as aphosphorescent dopant.

In embodiments, the emission layer may be a blue emission layer.

In embodiments, an electronic apparatus may include: a thin-filmtransistor; and the light-emitting device, wherein the thin-filmtransistor may include a source electrode, a drain electrode, anactivation layer, and a gate electrode. The first electrode of thelight-emitting device may be electrically connected to one of the sourceelectrode and the drain electrode of the thin-film transistor.

The term “middle layer” as used herein refers to a single layer and/orall layers between the first electrode and the second electrode of thelight-emitting device. The “middle layer” may include an organicmaterial, an inorganic material, or any combination thereof.

DESCRIPTION OF THE FIGURE

The FIGURE is a schematic cross-sectional view of a light-emittingdevice 10 according to an embodiment. The light-emitting device 10includes a first electrode 110, a middle layer 150, and a secondelectrode 190.

Hereinafter, the structure of the light-emitting device 10 according toan embodiment and a method of manufacturing the light-emitting device 10will be described in connection with the FIGURE.

[First Electrode 110]

In the FIGURE, a substrate may be disposed under the first electrode 110or above the second electrode 190. The substrate may be a glasssubstrate or a plastic substrate.

The first electrode 110 may be formed by depositing or sputtering amaterial for forming the first electrode 110 on the substrate. When thefirst electrode 110 is an anode, a high work function material that caneasily inject holes may be used as a material for a first electrode.

The first electrode 110 may be a reflective electrode, asemi-transmissive electrode, or a transmissive electrode. When the firstelectrode 110 is a transmissive electrode, a material for forming afirst electrode may be indium tin oxide (ITO), indium zinc oxide (IZO),tin oxide (SnO₂), zinc oxide (ZnO), or any combinations thereof, butembodiments are not limited thereto. In embodiments, when the firstelectrode 110 is a semi-transmissive electrode or a reflectiveelectrode, a material for forming a first electrode may be magnesium(Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium(Ca), magnesium-indium (Mg-ln), magnesium-silver (Mg—Ag), or anycombinations thereof, but embodiments are not limited thereto.

The first electrode 110 may have a single-layered structure consistingof a single layer or a multi-layered structure including multiplelayers. For example, the first electrode 110 may have a three-layeredstructure of ITO/Ag/ITO, but the structure of the first electrode 110 isnot limited thereto.

[Middle Layer 150]

The middle layer 150 may be disposed on the first electrode 110. Themiddle layer 150 may include an emission layer.

The middle layer 150 may further include a hole transport regiondisposed between the first electrode 110 and the emission layer and anelectron transport region disposed between the emission layer and thesecond electrode 190.

The middle layer 150 may further include a metal-containing compoundssuch as organometallic compounds, inorganic materials such as quantumdots, and the like, in addition to various organic materials.

[Hole Transport Region in Middle Layer 150]

The hole transport region may have: i) a single-layered structureconsisting of a single layer consisting of a single material, ii) asingle-layered structure consisting of a single layer consisting ofdifferent materials, or iii) a multi-layered structure includingmultiple layers including different materials.

The hole transport region may include a hole injection layer (HIL), ahole transport layer (HTL), an emission auxiliary layer, an electronblocking layer (EBL), or any combination thereof.

For example, the hole transport region may have a multi-layeredstructure including a hole injection layer/hole transport layerstructure, a hole injection layer/hole transport layer/emissionauxiliary layer structure, a hole injection layer/emission auxiliarylayer structure, a hole transport layer/emission auxiliary layerstructure, or a hole injection layer/hole transport layer/electronblocking layer structure, wherein, in each structure, layers are stacked(or disposed) sequentially from the first electrode 110, but embodimentsare not limited thereto.

The hole transport region may include a compound represented by Formula201, a compound represented by Formula 202, or any combination thereof:

In Formulae 201 and 202,

L₂₀₁ to L₂₀₄ may each independently be a substituted or unsubstitutedC₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, or a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

L₂₀₅ may be *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a substituted or unsubstitutedC₁-C₂₀ alkylene group, a substituted or unsubstituted C₂-C₂₀ alkenylenegroup, a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substitutedor unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted orunsubstituted C₆-C₆₀ arylene group, a substituted or unsubstitutedC₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalentnon-aromatic condensed polycyclic group, or a substituted orunsubstituted divalent non-aromatic condensed heteropolycyclic group,

xa1 to xa4 may each independently be 0, 1, 2, or 3 (for example, 0, 1,or 2),

xa5 may be an integer from 1 to 10 (for example, 1, 2, 3, or 4), and

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, or a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.

For example, in Formula 202, R₂₀₁ and R₂₀₂ may optionally be linked toeach other via a single bond, a dimethyl-methylene group, or adiphenyl-methylene group, and R₂₀₃ and R₂₀₄ may optionally be linked toeach other via a single bond, a dimethyl-methylene group, or adiphenyl-methylene group.

In one embodiment, i) at least one of R₂₀₁ to R₂₀₃ of Formula 201 andii) at least one of R₂₀₁ to R₂₀₄ of Formula 202 may each independentlybe selected from a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, an indeno phenanthrenyl group, a pyridinyl group,a pyrrolyl group, a thiophenyl group, a furanyl group, an indolyl group,a benzoindolyl group, an isoindolyl group, a benzoisoindolyl group, abenzosilolyl group, a benzothiophenyl group, a benzofuranyl group, acarbazolyl group, a dibenzosilolyl group, a dibenzothiophenyl group, ora dibenzofuranyl group, each unsubstituted or substituted withdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group,a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, acyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group,a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl groupsubstituted with —F, a naphthyl group, a phenanthrenyl group, an indenylgroup, a fluorenyl group, a dimethylfluorenyl group, a diphenylafluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adimethyla benzofluorenyl group, a diphenyla benzofluorenyl group, anindeno phenanthrenyl group, a dimethylindeno phenanthrenyl group, adiphenylindeno phenanthrenyl group, a pyridinyl group, a pyrrolyl group,a thiophenyl group, a furanyl group, an indolyl group, phenylan indolylgroup, a benzoindolyl group, phenylbenzoindolyl group, an isoindolylgroup, phenylan isoindolyl group, a benzoisoindolyl group,phenylbenzoisoindolyl group, a benzosilolyl group, adimethylbenzosilolyl group, a diphenylbenzosilolyl group, abenzothiophenyl group, a benzofuranyl group, a carbazolyl group, aphenylcarbazolyl group, a biphenylcarbazolyl group, a dibenzosilolylgroup, a dimethyla dibenzosilolyl group, a diphenyla dibenzosilolylgroup, a dibenzothiophenyl group, and a dibenzofuranyl group, butembodiments are not limited thereto.

In one embodiment, the compound represented by Formula 201 or 202 mayinclude at least one a carbazole group.

In one embodiment, the compound represented by Formula 201 may notinclude a carbazole group.

In one embodiment, the compound represented by Formula 201 may berepresented by Formula 201A-1:

L₂₀₃, xa3, and R₂₀₃ in Formula 201A-1 are the same as described above,and R₂₁₁ to R₂-16 may each independently be hydrogen, deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a naphthyl group, a phenanthrenyl group, an indenyl group, afluorenyl group, a dimethylfluorenyl group, a diphenyla fluorenyl group,a spiro-bifluorenyl group, a benzofluorenyl group, a dimethylabenzofluorenyl group, a diphenyla benzofluorenyl group, an indenophenanthrenyl group, a dimethylindeno phenanthrenyl group, adiphenylindeno phenanthrenyl group, a pyridinyl group, a pyrrolyl group,a thiophenyl group, a furanyl group, an indolyl group, phenylan indolylgroup, a benzoindolyl group, phenylbenzoindolyl group, an isoindolylgroup, phenylan isoindolyl group, a benzoisoindolyl group,phenylbenzoisoindolyl group, a benzosilolyl group, adimethylbenzosilolyl group, a diphenylbenzosilolyl group, abenzothiophenyl group, a benzofuranyl group, a carbazolyl group, aphenylcarbazolyl group, a biphenylcarbazolyl group, a dibenzosilolylgroup, a dimethyla dibenzosilolyl group, a diphenyla dibenzosilolylgroup, a dibenzothiophenyl group, or a dibenzofuranyl group.

The hole transport region may include one of Compounds HT1 to HT44,m-MTDATA, TDATA, 2-TNATA, NPB(NPD), (3-NPB, TPD, Spiro-TPD, Spiro-NPB,methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine(TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (PANI/CSA),polyaniline/poly(4-styrenesulfonate) (PANI/PSS), or any combinationthereof, but embodiments are not limited thereto:

A thickness of the hole transport region may be in a range of about 100Å to about 10,000 Å. In an embodiment, the thickness of the holetransport region may be in a range of about 100 Å to about 1,000 Å. Whenthe hole transport region includes at least one selected from a holeinjection layer and a hole transport layer, the thickness of the holeinjection layer may be in a range of about 100 Å to about 9,000 Å, andthe thickness of the hole transport layer may be in a range of about 50Å to about 2,000 Å. In an embodiment, the thickness of the holeinjection layer may be in a range of about 100 Å to about 1,000 Å. In anembodiment, the thickness of the hole transport layer may be in a rangeof about 100 Å to about 1,500 Å. When the thicknesses of the holetransport region, the hole injection layer, and the hole transport layerare within these ranges, satisfactory hole transporting characteristicsmay be obtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase light-emission efficiency bycompensating for an optical resonance distance according to thewavelength of light emitted by an emission layer, and the electronblocking layer may block the flow of electrons from an electrontransport region. The emission auxiliary layer and the electron blockinglayer may include the materials as described above.

[p-Dopant]

The hole transport region may include, in addition to these materials, acharge-generation material for the improvement of conductive properties.The charge-generation material may be homogeneously or non-homogeneouslydispersed in the hole transport region.

The charge-generation material may be, for example, a p-dopant.

In one embodiment, the lowest unoccupied molecular orbital (LUMO) energylevel of the p-dopant may be −3.5 eV or less.

The p-dopant may include a quinone derivative, a metal oxide, a cyanogroup-containing compound, or any combination particular, butembodiments are not limited thereto.

In one embodiment, the p-dopant may include

a quinone derivative such as TCNQ, F4-TCNQ, and the like;

a metal oxide, such as tungsten oxide or molybdenum oxide;

a cyano group-containing compound such as HAT-CN and the like;

a compound represented by Formula 221; or

any combination thereof.

However, embodiments are not limited thereto:

In Formula 221,

R₂₂₁ to R₂₂₃ may each independently be a substituted or unsubstitutedC₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, or a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group, and at least one of R₂₂₁to R₂₂₃ may each independently be a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroarylgroup, a monovalent non-aromatic condensed polycyclic group, or amonovalent non-aromatic condensed heteropolycyclic group, eachunsubstituted or substituted with: a cyano group; —F; —Cl; —Br; —I; aC₁-C₂₀ alkyl group substituted with at least one cyano group; a C₁-C₂₀alkyl group substituted with at least one —F; a C₁-C₂₀ alkyl groupsubstituted with at least one —Cl; a C₁-C₂₀ alkyl group substituted withat least one —Br; a C₁-C₂₀ alkyl group substituted with at least one —I;or any combination thereof.

[Emission Layer in Middle Layer 150]

When the light-emitting device 10 is a full-color light-emitting device,the emission layer may be patterned into a red emission layer, a greenemission layer, and/or a blue emission layer, according to a sub-pixel.In embodiments, the emission layer may have a stacked structure of twoor more layers of a red emission layer, a green emission layer, and ablue emission layer, in which the two or more layers contact each otheror are separated from each other. In embodiments, the emission layer mayinclude two or more materials of a red light-emitting material, a greenlight-emitting material, and a blue light-emitting material, in whichthe two or more materials are mixed with each other in a single layer toemit white light.

The emission layer may include a host and a dopant. The dopant mayinclude a phosphorescent dopant, a fluorescent dopant, or anycombination thereof.

The amount of the dopant in the emission layer may be from about 0.01 toabout 15 parts by weight based on 100 parts by weight of the host.However, embodiments are not limited thereto.

In embodiments, the emission layer may include a quantum dot.

A thickness of the emission layer may be in a range of about 100 Å toabout 1,000 Å. In an embodiment, the thickness of the emission layer maybe in a range of about 200 Å to about 600 Å. When the thickness of theemission layer is within this range, excellent light-emissioncharacteristics may be obtained without a substantial increase indriving voltage.

[Host in Emission Layer]

In embodiments, the host may include a compound represented by Formula301 below:[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21)  <Formula 301>

In Formula 301,

Ar₃₀₁ may be a substituted or unsubstituted C₅-C₃₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xb11 may be 1, 2, or 3,

L₃₀₁ may be a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substitutedor unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted orunsubstituted C₆-C₆₀ arylene group, a substituted or unsubstitutedC₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalentnon-aromatic condensed polycyclic group, or a substituted orunsubstituted divalent non-aromatic condensed heteropolycyclic group,

xb1 may be 0, 1, 2, 3, 4, or 5,

R₃₀₁ may be deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, a substituted or unsubstituted C₁-C₆₀ alkyl group,a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted orunsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstitutedC₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkylgroup, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂),—B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), or —P(═O)(Q₃₀₁)(Q₃₀₂),

xb21 may be 1, 2, 3, 4, or 5, and

Q₃₀₁ to Q₃₀₃ are the same as described in connection with Q₁.

In embodiments, when xb11 in Formula 301 is 2 or more, two or moreAr₃₀₁(s) may be linked to each other via a single bond.

In one embodiment, the host may include a compound represented byFormula 301-1, a compound represented by Formula 301-2, or anycombination embodiment:

In Formulae 301-1 and 301-2,

ring A₃₀₁ to ring A₃₀₄ may each independently be a C₅-C₆₀ carbocyclicgroup or a C₁-C₆₀ heterocyclic group,

X₃₀₁ may be O, S, N-[(L₃₀₄)_(xb4)-R₃₀₄], C(R₃₀₄)(R₃₀₅), orSi(R₃₀₄)(R₃₀₅),

xb22 and xb23 may each independently be 0, 1, or 2,

L₃₀₁, xb1, and R₃₀₁ are the same as described above,

L₃₀₂ to L₃₀₄ are each independently the same as described in connectionwith L₃₀₁,

xb2 to xb4 each independently the same as described in connection withxb1, and

R₃₀₂ to R₃₀₅ and R₃₁₁ to R₃₁₄ are the same as described in connectionwith R₃₀₁.

In one embodiment, the host may include an alkaline earth-metal complex.For example, the host may be a Be complex (for example, Compound H55), aMg complex, a Zn complex, or any combination thereof.

In one embodiment, the host may include one of Compounds H1 to H120,9,10-di(2-naphthyl)anthracene (ADN),2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN),9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN),4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene(mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), or any combinationthereof, but embodiments are not limited thereto:

[Phosphorescent Dopant Included in Emission Layer in Middle Layer 150]

The phosphorescent dopant may include the trimetallic complex of Formula1 according to an embodiment.

The phosphorescent dopant may further comprise an organometalliccompound represented by Formula 401, in addition to the trimetalliccomplex of Formula 1 according to an embodiment:M(L₄₀₁)_(xc1)(L₄₀₂)_(xc2)  <Formula 401>

In Formulae 401 and 402,

M may be transition metal (for example, iridium (Ir), platinum (Pt),palladium (Pd), osmium (Os), titanium (Ti), gold (Au) hafnium (Hf),europium (Eu), terbium (Tb), rhodium (Rh), rhenium (Re), or thulium(Tm)),

L₄₀₁ may be a ligand represented by Formula 402, and xc1 may be 1, 2, or3, wherein, when xc1 is 2 or more, two or more L₄₀₁(s) may be identicalto or different from each other,

L₄₀₂ may be an organic ligand, xc2 may be 0, 1, 2, 3, or 4, and when xc2is 2 or more, two or more of L₄₀₂(s) may be identical to or differentfrom each other,

X₄₀₁ and X₄₀₂ may each independently be nitrogen or carbon,

ring A₄₀₁ and ring A₄₀₂ may each independently be selected from a C₅-C₆₀carbocyclic group or a C₁-C₆₀ heterocyclic group,

T₄₀₁ may be a single bond, *—C(═O)—*′, *—N(Q₄₁₁)-*′, *—C(Q₄₁₁)(Q₄₁₂)-*′,*—C(Q₄₁₁)═C(Q₄₁₂)-*′, *—C(Q₄₁₁)=*′, or *═C(Q₄₁₁)=*′,

X₄₀₃ and X₄₀₄ may each independently be a chemical bond (for example, acovalent bond or a coordinate bond), O, S, N(Q₄₁₃), B(Q₄₁₃), P(Q₄₁₃),C(Q₄₁₃)(Q₄₁₁), or Si(Q₄₁₃)(Q₄₁₁),

Q₄₁₁ to Q₄₁₄ are the same as described in connection with Q₁,

R₄₀₁ and R₄₀₂ may each independently be hydrogen, deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, a substitutedor unsubstituted C₁-C₂₀ alkyl group, a substituted or unsubstitutedC₁-C₂₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkylgroup, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, and asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂),—B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄OI), or —P(═O)(Q₄₀₁)(Q₄₀₂),

Q₄₀₁ to Q₄₀₃ are the same as described in connection with Q₁,

xc11 and xc12 may each independently be an integer from 0 to 10, and

* and *′ in Formula 402 each indicate a binding site to M in Formula401.

In embodiments, in Formula 402, i) X₄₀₁ may be nitrogen, and X₄₀₂ may becarbon, or ii) X₄₀₁ and X₄₀₂ may be nitrogen at the same time.

In embodiments, when xc1 in Formula 402 is 2 or more, two ring A₄₀₁(s)in two or more L₄₀₁(s) may optionally be linked to each other via T₄₀₂,which is a linking group, or two ring A₄₀₂(s) in two or more L₄₀₁(s) mayoptionally be linked to each other via T₄₀₃, which is a linking group(see Compounds PD1 to PD4 and PD7). T₄₀₂ and T₄₀₃ are the same asdescribed in connection with T₄₀₁.

L₄₀₂ in Formula 401 may be an organic ligand. For example, L₄₀₂ may behalogen group, a diketone group (for example, an acetylacetonate group),a carboxylic acid group (for example, picolinate group), —C(═O), anisonitril group, a —CN group, a phosphorus group (for example, aphosphine group or a phosphite group), or any combination thereof, butembodiments are not limited thereto.

The phosphorescent dopant may include, for example, one of the followingCompound PD1 to PD25, or any combination, but embodiments are notlimited thereto:

[Fluorescent Dopant in Emission Layer]

The fluorescent dopant may include an arylamine compound or astyrylamine compound.

For example, the fluorescent dopant may include a compound representedby Formula 501:

In Formula 501,

Ar₅₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

L₅₀₁ to L₅₀₃ may each independently be a substituted or unsubstitutedC₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, or a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xd1 to xd3 may each independently be 0, 1, 2, or 3,

R₅₀₁ and R₅₀₂ may each independently be a substituted or unsubstitutedC₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, or a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and

xd4 may be 1, 2, 3, 4, 5, or 6.

For example, Ar₅₀₁ in Formula 501 may be a condensed cyclic ring (forexample, an anthracene group, a chrysene group, a pyrene group, etc.) inwhich three or more monocyclic groups are condensed.

In one embodiment, xd4 in Formula 501 may be 2, but embodiments are notlimited thereto.

For example, the fluorescent dopant may include: one of Compounds FD1 toFD36; DPVBi; DPAVBi; or any combination thereof:

[Electron Transport Region in Middle Layer 150]

The electron transport region may have: i) a single-layered structureconsisting of a single layer consisting of a single material, ii) asingle-layered structure consisting of a single layer consisting ofdifferent materials, or iii) a multi-layered structure includingmultiple layers including different materials.

The electron transport region may include a buffer layer, a holeblocking layer, an electron control layer, an electron transport layer,an electron injection layer, or any combination thereof, but embodimentsare not limited thereto.

For example, the electron transport region may have an electrontransport layer/electron injection layer structure, a hole blockinglayer/electron transport layer/electron injection layer structure, anelectron control layer/electron transport layer/electron injection layerstructure, or a buffer layer/electron transport layer/electron injectionlayer structure, wherein for each structure, constituting layers aresequentially stacked (or disposed) from an emission layer. However,embodiments of the structure of the electron transport region are notlimited thereto.

The electron transport region (for example, the buffer layer, the holeblocking layer, the electron control layer, or the electron transportlayer in the electron transport region) may include a metal-freecompound including at least one π-electron deficient nitrogen-containingcyclic group, which may easily accept electrons.

The “π-electron deficient nitrogen-containing cyclic group” may be aC₁-C₆₀ heterocyclic group which has, as a ring-forming moiety, at leastone *—N═*′ moiety.

For example, the “π-electron-deficient nitrogen-containing cyclic group”may be i) a first ring, ii) a condensed cyclic group in which two ormore first rings are condensed to each other, or iii) a condensed cyclicgroup in which at least one first ring and at least one second ring arecondensed, wherein the first ring is a heteromonocyclic group (forexample, an imidazole group, a pyridine group, a triazine group, etc.)which includes, as a ring-forming moiety, at least one *—N═*′ moiety,and the second ring is a cyclic group (for example, a benzene group, adibenzofuran group, a carbazole group, etc.) which does not include, asa ring-forming moiety, *—N═*′ moiety.

Examples of the π-electron-deficient nitrogen-containing cyclic groupare a pyridine group, a pyrimidine group, a pyrazine group, a pyridazinegroup, a triazine group, a quinoline group, a benzoquinoline group, anisoquinoline group, a benzoisoquinoline group, a quinoxaline group, abenzoquinoxaline group, a quinazoline group, a benzoquinazoline group, acinnoline group, a phenanthroline group, a phthalazine group, anaphthyridine group, an azacarbazole group, an azafluorene group, anazadibenzosilole group, an azadibenzothiophene group, an azadibenzofurangroup, a pyrazole group, an imidazole group, a triazole group, atetrazole group, an oxazole group, an isooxazole group, a thiazolegroup, an isothiazole group, an oxadiazole group, a thiadiazole group, abenzopyrazole group, a benzimidazole group, a benzoxazole group, abenzothiazole group, a benzoxadiazole group, a benzothiadiazole group,an imidazopyridine group, an imidazopyrimidine group, an imidazotriazinegroup, an imidazopyrazine group, and an imidazopyridazine group, butembodiments are not limited thereto.

For example, the electron transport region may include a compoundrepresented by Formula 601 and including at least one π-electrondeficient nitrogen-containing cyclic group.[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21)  <Formula 601>

In Formula 601,

Ar₆₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xe11 may be 1, 2, or 3,

L₆₀₁ may be a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substitutedor unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted orunsubstituted C₆-C₆₀ arylene group, a substituted or unsubstitutedC₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalentnon-aromatic condensed polycyclic group, or a substituted orunsubstituted divalent non-aromatic condensed heteropolycyclic group,

xe1 may be 0, 1, 2, 3, 4, or 5,

R₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁),—S(═O)₂(Q₆OI), or —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁ to Q₆₀₃ are the same as described in connection with Q₁, and

xe21 may be 1, 2, 3, 4, or 5.

For example, at least one of Ar₆₀₁, L₆₀₁, and R₆₀₁ of Formula 601 mayeach independently include at least one π-electron deficientnitrogen-containing ring.

In embodiments, when xe11 in Formula 601 is 2 or more, two or moreAr₆₀₁(s) may be linked to each other via a single bond.

In one embodiment, Ar₆₀₁ in Formula 601 may be a substituted orunsubstituted anthracene group.

In one embodiment, the electron transport region may include a compoundrepresented by Formula 601-1:

In Formula 601-1,

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N orC(R₆₁₆), and at least one selected from X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ may be understood by referring to the description presentedin connection with L₆₀₁,

xe611 to xe613 may be understood by referring to the descriptionpresented in connection with xe1,

R₆₁₁ to R₆₁₃ may be understood by referring to the description presentedin connection with R₆₀₁,

R₆₁₄ to R₆₁₆ may each independently be hydrogen, deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, or a naphthyl group.

For example, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may eachindependently be 0, 1, or 2.

The electron transport region may include one of Compounds ET1 to ET36,2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP),4,7-Diphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq, TAZ, NTAZ, or anycombination thereof, but embodiments are not limited thereto:

Thicknesses of the buffer layer, the hole blocking layer, and theelectron control layer may each be in a range of about 20 Å to about1,000 Å. In an embodiment, the thickness of the buffer layer may be in arange of about 30 Å to about 300 Å. In an embodiment, the thickness ofthe hole blocking layer may be in a range of about 30 Å to about 300 Å.In an embodiment, the thickness of the electron control layer may be ina range of about 30 Å to about 300 Å. When the thicknesses of the bufferlayer, the hole blocking layer, and the electron control layer arewithin these ranges, excellent hole blocking characteristics or electroncontrol characteristics may be obtained without a substantial increasein driving voltage.

A thickness of the electron transport layer may be in a range of about100 Å to about 1,000 Å. In an embodiment, the thickness of the electrontransport layer may be in a range of about 150 Å to about 500 Å. Whenthe thickness of the electron transport layer is within the rangedescribed above, the electron transport layer may have satisfactoryelectron transport characteristics without a substantial increase indriving voltage.

The electron transport region (for example, the electron transport layerin the electron transport region) may further include, in addition tothe materials described above, a metal-containing material.

The metal-containing material may include an alkali metal complex, analkaline earth-metal complex, or any combination thereof. The alkalimetal complex may be a Li ion, a Na ion, a K ion, an Rb ion, or a Csion, and the alkaline earth-metal complex may be a Be ion, a Mg ion, aCa ion, a Sr ion, or a Ba ion. A ligand coordinated with the metal ionof the alkali metal complex or the alkaline earth-metal complex may be ahydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, ahydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, ahydroxy phenylthiazole, a hydroxy diphenyloxadiazole, a hydroxydiphenylthiadiazole, a hydroxy phenylpyridine, a hydroxyphenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, aphenanthroline, or a cyclopentadiene, but embodiments are not limitedthereto.

For example, the metal-containing material may include a Li complex. TheLi complex may include, for example, Compound ET-D1 (LiQ) or ET-D2:

The electron transport region may include an electron injection layerthat facilitates electron injection from the second electrode 190. Theelectron injection layer may contact (for example, directly contact) thesecond electrode 190.

The electron injection layer may have: i) a single-layered structureconsisting of a single layer consisting of a single material, ii) asingle-layered structure consisting of a single layer consisting ofdifferent materials, or iii) a multi-layered structure includingmultiple layers including different materials.

The electron injection layer may include an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal-containing compound, analkaline earth-containing metal compound, a rare earth metal-containingcompound, an alkali metal complex, an alkaline earth-metal complex, arare earth metal complex, or any combinations thereof.

The alkali metal may include Li, Na, K, Rb, Cs, or any combinationthereof. The alkaline earth metal may include Mg, Ca, Sr, Ba, or anycombination thereof. The rare earth metal may include Sc, Y, Ce, Tb, Yb,Gd, or any combination thereof.

The alkali metal-containing compound, the alkaline earthmetal-containing compound, and the rare earth metal-containing compoundmay be oxides and halides (for example, fluorides, chlorides, bromides,or iodides) of the alkali metal, the alkaline earth-metal, and the rareearth metal, or any combination thereof.

The alkali metal-containing compound may be alkali metal oxides, such asLi₂O, Cs₂O, or K₂O, and alkali metal halides, such as LiF, NaF, CsF, KF,LiI, NaI, CsI, or Kl, or any combination thereof. The alkalineearth-metal containing compound may include alkaline earth-metal oxides,such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O (0<x<1), or Ba_(x)Ca_(1-x)O(0<x<1). The rare earth metal-containing compound may include YbF₃,ScF₃, SCO₃, Y₂O₃, Ce₂O₃, GdF₃, TbF₃, YbI₃, ScI₃, TbI₃, or anycombination thereof.

The alkali metal complex, the alkaline earth metal complex, and the rareearth metal complex may include i) one of ions of the alkali metal, thealkaline earth metal, and the rare earth metal and ii), as a ligandlinked to the metal ion, for example, hydroxyquinoline, hydroxyanisoquinoline, hydroxybenzoquinoline, hydroxyacridine,hydroxyphenanthridine, hydroxyphenyloxazole, hydroxyphenylthiazole,hydroxydiphenyloxadiazole, hydroxydiphenylthiadiazole,hydroxyphenylpyridine, hydroxyphenyl benzimidazole,hydroxyphenylbenzothiazole, bipyridine, phenanthroline, cyclopentadiene,or any combination thereof, but embodiments are not limited thereto.

The electron injection layer may consist of an alkali metal, alkalineearth metal, a rare earth metal, an alkali metal-containing compound,alkaline earth metal-containing compound, a rare earth metal-containingcompound, an alkali metal complex, an alkaline earth metal complex, arare earth metal complex, or any combination thereof, or may furtherinclude an organic material (for example, a compound represented byFormula 601). When the electron injection layer further includes anorganic material, an alkali metal, an alkaline earth metal, a rare earthmetal, an alkali metal-containing compound, an alkaline earthmetal-containing compound, a rare earth metal-containing compound, analkali metal complex, an alkaline earth-metal complex, a rare earthmetal complex, or any combinations thereof may be homogeneously ornon-homogeneously dispersed in a matrix including the organic material.

A thickness of the electron injection layer may be in a range of about 1Å to about 100 Å. In an embodiment, the thickness of the electroninjection layer may be in a range of about 3 Å to about 90 Å. When thethickness of the electron injection layer is within the range describedabove, the electron injection layer may have satisfactory electroninjection characteristics without a substantial increase in drivingvoltage.

[Second Electrode 190]

The second electrode 190 may be disposed on the middle layer 150 havingsuch a structure. The second electrode 190 may be a cathode, which is anelectron injection electrode, and as the material for the secondelectrode 190, a metal, an alloy, an electrically conductive compound,or any combination thereof, each having a low work function, may beused.

The second electrode 190 may include lithium (Li), silver (Ag),magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca),magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ITO, IZO, or anycombination thereof, but embodiments are not limited thereto. The secondelectrode 190 may be a transmissive electrode, a semi-transmissiveelectrode, or a reflective electrode.

The second electrode 190 may have a single-layered structure, or amulti-layered structure including two or more layers.

[Capping Layer]

A first capping layer may be disposed outside the first electrode 110,and/or a second capping layer may be disposed outside the secondelectrode 190. In detail, the light-emitting device 10 may have astructure in which the first capping layer, the first electrode 110, themiddle layer 150, and the second electrode 190 are sequentially stacked(or disposed) in this stated order, a structure in which the firstelectrode 110, the middle layer 150, the second electrode 190, and thesecond capping layer are sequentially stacked (or disposed) in thisstated order, or a structure in which the first capping layer, the firstelectrode 110, the middle layer 150, the second electrode 190, and thesecond capping layer are sequentially stacked (or disposed) in thisstated order.

Light generated in an emission layer of the middle layer 150 of thelight-emitting device 10 may be emitted toward the outside through thefirst electrode 110 and the first capping layer, each of which may be asemi-transmissive electrode or a transmissive electrode, or lightgenerated in an emission layer of the middle layer 150 of thelight-emitting device 10 may be emitted toward the outside through thesecond electrode 190 and the second capping layer, each of which may bea semi-transmissive electrode or a transmissive electrode.

The first capping layer and the second capping layer may increaseexternal luminescence efficiency according to the principle ofconstructive interference.

The first capping layer and the second capping layer may eachindependently be an organic capping layer including an organic material,an inorganic capping layer including an inorganic material, or acomposite capping layer including an organic material and an inorganicmaterial.

At least one selected from the first capping layer and the secondcapping layer may each independently include a carbocyclic compound, aheterocyclic compound, an amine group-containing compound, a porphyrinederivative, a phthalocyanine derivative, a naphthalocyanine derivative,an alkali metal complex, an alkaline earth metal complex, or acombination thereof. The carbocyclic compound, the heterocycliccompound, and the amine group-containing compound may be optionallysubstituted with a substituent containing O, N, S, Se, Si, F, Cl, Br, I,or any combination thereof. In one embodiment, at least one of the firstcapping layer and the second capping layer may each independentlyinclude an amine group-containing compound.

For example, at least one of the first capping layer and second cappinglayer may each independently include a compound represented by Formula201, a compound represented by Formula 202, or any combination thereof.

In embodiments, at least one of the first capping layer and the secondcapping layer may each independently include a compound selected fromCompounds HT28 to HT33, Compounds CP1 to CP5, or any combinationthereof, but embodiments are not limited thereto:

[Apparatus]

The light-emitting device 10 may be included in various apparatuses. Forexample, a light-emitting apparatus, an authentication apparatus, or anelectronic apparatus, which includes the light-emitting device 10, maybe provided.

The light-emitting apparatus may further include, in addition to thelight-emitting device 10, a color filter. The color filter may bedisposed on at least one traveling direction of light emitted from alight-emitting device. For example, light emitted from thelight-emitting device 10 may be blue light, but embodiments are notlimited thereto. The light-emitting device 10 is the same as describedabove.

The light-emitting apparatus may include a first substrate. The firstsubstrate may include subpixels, and the color filter may include colorfilter areas respectively corresponding to the subpixels.

A pixel-defining film may be formed between the subpixels to define eachof the subpixels.

The color filter may further include light blocking patterns disposedbetween the color filter areas.

The color filter areas may include a first color filter area emittingfirst color light, a second color filter area emitting second colorlight, and/or a third color filter area emitting third color light, andthe first color light, the second color light, and/or the third colorlight may have different maximum emission wavelengths from one another.For example, the first color light may be red light, the second colorlight may be green light, and the third color light may be blue light,but embodiments are not limited thereto. For example, each of the colorfilter areas may include a quantum dot, but embodiments are not limitedthereto. In detail, the first color filter area may include a redquantum dot, the second color filter area may include a green quantumdot, and the third color filter area may not include a quantum dot. Thequantum dot is the same as described above. Each of the first colorfilter area, the second color filter area, and/or the third color filterarea may include a scattering component, but embodiments are not limitedthereto.

For example, the light-emitting device 10 may emit first light, thefirst color filter area may absorb the first light to emit firstfirst-color light, the second color filter area may absorb the firstlight to emit second first-color light, and the third color filter areamay absorb the first light to emit third first-color light. In thisregard, the first first-color light, the second first-color light, andthe third first-color light may have different maximum emissionwavelengths from one another. In detail, the first light may be bluelight, the first first-color light may be red light, the secondfirst-color light may be green light, and the third first-color lightmay be blue light, but embodiments are not limited thereto.

The light-emitting apparatus may further include, in addition to thelight-emitting device 10 as described above, a thin-film transistor. Thethin-film transistor may include a source electrode, a drain electrode,and an activation layer, wherein any one of the source electrode and thedrain electrode may be electrically connected to any one of the firstelectrode 110 and the second electrode 190 of the light-emitting device10.

The thin-film transistor may further include a gate electrode, a gateinsulation layer, or the like.

The activation layer may include crystalline silicon, amorphous silicon,an organic semiconductor, an oxide semiconductor, or the like, butembodiments are not limited thereto.

The light-emitting apparatus may further include a sealing portion forsealing a light-emitting device. The sealing portion may be disposedbetween the color filter and the light-emitting device 10. The sealingportion may allow light from the light-emitting device 10 to be emittedto the outside and may block outside air and moisture from penetratinginto the light-emitting device 10 at the same time. The sealing portionmay be a sealing substrate including a transparent glass substrate or aplastic substrate. The sealing portion may be a thin-film encapsulationlayer including organic layers and/or inorganic layers. When the sealingportion is the thin-film encapsulation layer, the light-emittingapparatus may be flexible.

The light-emitting apparatus may be used as various displays, lightsources, and the like.

The authentication apparatus may be, for example, a biometricauthentication apparatus for authenticating an individual by usingbiometric information of a biometric body (for example, from afingertip, a pupil, or the like).

The authentication apparatus may further include, in addition to thelight-emitting device, a biometric information collector.

The electronic apparatus may be applied to personal computers (forexample, a mobile personal computer), mobile phones, digital cameras,electronic organizers, electronic dictionaries, electronic gamemachines, medical instruments (for example, electronic thermometers,sphygmomanometers, blood glucose meters, pulse measurement devices,pulse wave measurement devices, electrocardiogram displays, ultrasonicdiagnostic devices, or endoscope displays), fish finders, variousmeasuring instruments, meters (for example, meters for a vehicle, anaircraft, and a vessel), projectors, and the like, but embodiments arenot limited thereto.

[Preparation Method]

Layers constituting the hole transport region, an emission layer, andlayers constituting the electron transport region may be formed in aregion by using one or more suitable methods selected from vacuumdeposition, spin coating, casting, Langmuir-Blodgett (LB) deposition,ink-jet printing, laser-printing, and laser-induced thermal imaging.

When layers constituting the hole transport region, an emission layer,and layers constituting the electron transport region are formed byvacuum deposition, the deposition may be performed at a depositiontemperature of about 100° C. to about 500° C., a vacuum degree of about10⁻⁸ torr to about 10⁻³ torr, and a deposition speed of about 0.01 Å/secto about 100 Å/sec by taking into account a material to be included in alayer to be formed and the structure of a layer to be formed.

When layers constituting the hole transport region, an emission layer,and layers constituting the electron transport region are formed by spincoating, the spin coating may be performed at a coating speed of about2,000 rpm to about 5,000 rpm and at a heat treatment temperature ofabout 80° C. to about 200° C. by taking into account a material to beincluded in a layer to be formed and the structure of a layer to beformed.

[Definitions of Substituents]

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear orbranched aliphatic hydrocarbon monovalent group with 1 to 60 carbonatoms, and examples thereof are a methyl group, an ethyl group, ann-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group,an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentylgroup, a neopentyl group, an isopentyl group, a sec-pentyl group, a3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexylgroup, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, anisoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octylgroup, an isooctyl group, a sec-octyl group, a tert-octyl group, ann-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group,an n-decyl group, an isodecyl group, a sec-decyl group, or a tert-decylgroup. The term “C₁-C₆₀ alkylene group” as used herein refers to adivalent group having the same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a monovalenthydrocarbon group having at least one carbon-carbon double bond in themiddle or at the terminus of a C₂-C₆₀ alkyl group, and examples thereofinclude an ethenyl group, a propenyl group, and a butenyl group. Theterm “C₂-C₆₀ alkenylene group” as used herein refers to a divalent grouphaving the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a monovalenthydrocarbon group having at least one carbon-carbon triple bond in themiddle or at the terminus of a C₂-C₆₀ alkyl group, and examples thereofinclude an ethynyl group and a propynyl group. The term “C₂-C₆₀alkynylene group” as used herein refers to a divalent group having thesame structure as the C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalentgroup represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group),and examples thereof include a methoxy group, an ethoxy group, and anisopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalentsaturated hydrocarbon cyclic group with 3 to 10 carbon atoms, andexamples thereof are a cyclopropyl group, a cyclobutyl group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cycloctylgroup, an adamantanyl group, a norbornanyl group, a bicyclo[1.1.1]pentylgroup, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.1]heptyl, and abicyclo[2.2.2]octyl group. The term “C₃-C₁₀ cycloalkylene group” as usedherein refers to a divalent group having the same structure as theC₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to amonovalent cyclic group with 1 to 10 carbon atoms containing aheteroatom (for example, N, O, Si, P, S, or any combination thereof) asa ring-forming atom, and examples thereof are a 1,2,3,4-oxatriazolidinylgroup, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. Theterm “C₁-C₁₀ heterocycloalkylene group” as used herein refers to adivalent group having the same structure as the C₁-C₁₀ heterocycloalkylgroup.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to amonovalent monocyclic group that has 3 to 10 carbon atoms and at leastone carbon-carbon double bond in the ring thereof and no aromaticity,and non-limiting examples thereof include a cyclopentenyl group, acyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀cycloalkenylene group” as used herein refers to a divalent group havingthe same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to amonovalent cyclic group with 1 to 10 carbon atoms containing aheteroatom (for example, N, O, Si, P, S, or any combination thereof) asa ring-forming atom, wherein the ring has at least one a double bond.Examples of the C₁-C₁₀ heterocycloalkenyl group include a4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, anda 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylenegroup” as used herein refers to a divalent group having the samestructure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent grouphaving a carbocyclic aromatic system having 6 to 60 carbon atoms, andthe term “C₆-C₆₀ arylene group” as used herein refers to a divalentgroup having a carbocyclic aromatic system having 6 to 60 carbon atoms.Examples of the C₆-C₆₀ aryl group are a phenyl group, a pentalenylgroup, a naphthyl group, an azulenyl group, an indacenyl group, anacenaphthyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a heptalenyl group, a naphthacenyl group, a picenyl group, ahexacenyl group, a pentacenyl group, a rubicenyl group, a coronenylgroup, and an ovalenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀arylene group each include two or more rings, the rings may be fused toeach other.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalentgroup having a heterocyclic aromatic system in which a heteroatom (forexample, N, O, Si, P, S, or any combination specifically) is included asa ring-forming atom and the number of carbon atoms included is 1 to 60,and the term “C₁-C₆₀ heteroarylene group” as used herein refers to adivalent group having a heterocyclic aromatic system in which aheteroatom (for example, N, O, Si, P, S, or any combinationspecifically) is included as a ring-forming atom and the number ofcarbon atoms included is 1 to 60. Examples of the C₁-C₆₀ heteroarylgroup are a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, apyridazinyl group, a triazinyl group, a quinolinyl group, abenzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinylgroup, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinylgroup, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinylgroup, a phthalazinyl group, and a naphthyridinyl group. When the C₁-C₆₀heteroaryl group and the C₁-C₆₀ heteroarylene group each include two ormore rings, the rings may be condensed with each other.

The term “C₆-C₆₀ aryloxy group” as used herein refers to —OA₁₀₂ (whereinA₁₀₂ is the C₆-C₆₀ aryl group), and a C₆-C₆₀ arylthio group used hereinindicates —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as usedherein refers to a monovalent group (for example, having 8 to 60 carbonatoms) having two or more rings condensed with each other, only carbonatoms as ring-forming atoms, and no aromaticity in its entire molecularstructure. Examples of the monovalent non-aromatic condensed polycyclicgroup are an indenyl group, a fluorenyl group, a spiro-bifluorenylgroup, a benzofluorenyl group, an indeno phenanthrenyl group, and anindenon anthracenyl group. The term “divalent non-aromatic condensedpolycyclic group” as used herein refers to a divalent group having thesame structure as the monovalent non-aromatic condensed polycyclicgroup.

The term “monovalent non-aromatic condensed heteropolycyclic group” asused herein refers to a monovalent group in which two or more rings arecondensed to each other, which includes, as a ring-forming atom, aheteroatom (for example, N, O, Si, P, and S, or any combination thereof)other than carbon, and which has no aromaticity in its entire molecularstructure. Examples of the monovalent non-aromatic condensedheteropolycyclic group are a pyrrolyl group, a thiophenyl group, afuranyl group, an indolyl group, a benzoindolyl group, a naphthonindolyl group, an isoindolyl group, a benzoisoindolyl group, anaphthonisoindolyl group, a benzosilolyl group, a benzothiophenyl group,a benzofuranyl group, a carbazolyl group, a dibenzosilolyl group, adibenzothiophenyl group, a dibenzofuranyl group, an azacarbazolyl group,an azafluorenyl group, an azadibenzosilolyl group, anazadibenzothiophenyl group, an azadibenzofuranyl group, a pyrazolylgroup, an imidazolyl group, a triazolyl group, a tetrazolyl group, anoxazolyl group, an isoxazolyl group, a thiazolyl group, an isothiazolylgroup, an oxadiazolyl group, a thiadiazolyl group, a benzopyrazolylgroup, a benzimidazolyl group, a benzoxazolyl group, a benzothiazolylgroup, a benzoxadiazolyl group, a benzothiadiazolyl group, animidazopyridinyl group, an imidazopyrimidinyl group, an imidazotriazinylgroup, an imidazopyrazinyl group, an imidazopyridazinyl group, an indenocarbazolyl group, an indolocarbazolyl group, a benzofurocarbazolylgroup, a benzothienocarbazolyl group, a benzosilolocarbazolyl group, abenzoindolocarbazolyl group, a benzocarbazolyl group, abenzonaphthofuranyl group, a benzonaphthothiophenyl group, abenzonaphtho silolyl group, a benzofurodibenzofuranyl group, abenzofurodibenzothiophenyl group, and a benzothienodibenzothiophenylgroup. The term “divalent non-aromatic condensed heteropolycyclic group”as used herein refers to a divalent group having the same structure asthe monovalent non-aromatic condensed heteropolycyclic group.

The term “C₅-C₆₀ carbocyclic group” as used herein refers to amonocyclic or polycyclic group that includes only carbon as aring-forming atom and consists of 5 to 60 carbon atoms. The C₅-C₆₀carbocyclic group may be an aromatic carbocyclic group or a non-aromaticcarbocyclic group. The C₅-C₆₀ carbocyclic group may be a compound, suchas benzene, a monovalent group, such as a phenyl group, or a divalentgroup, such as a phenylene group. In embodiments, depending on thenumber of substituents connected to the C₅-C₆₀ carbocyclic group, theC₅-C₆₀ carbocyclic group may be a trivalent group or a quadrivalentgroup.

Examples of the C₅-C₆₀ carbocyclic group are a cyclopentadiene group, abenzene group, a pentalene group, a naphthalene group, an azulene group,an indacene group, acenaphthylene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a perylene group,a pentaphene group, a heptalene group, a naphthacene group, a picenegroup, a hexacene group, a pentacene group, a rubicene group, a coronenegroup, an ovalene group, an indene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, an indeno phenanthrenegroup, and an indenoanthracene group.

The term “C₁-C₆₀ heterocyclic group” as used herein refers to amonocyclic or polycyclic group which includes 1 to 60 carbon atoms and,as a ring-forming atom, a heteroatom (for example, N, O, Si, P, S, orany combination specifically), in addition to carbon (the carbon numbermay be 1 to 60). The C₁-C₆₀ heterocyclic group may be an aromaticheterocyclic group or a non-aromatic heterocyclic group. The C₁-C₆₀heterocyclic group may be a compound such as a pyridine, a monovalentgroup such as a pyridinyl group, or a divalent group such as apyridinylene group. In embodiments, depending on the number ofsubstituents connected to the C₁-C₆₀ heterocyclic group, the C₁-C₆₀heterocyclic group may be a trivalent group or a quadrivalent group.

Examples of the C₁-C₆₀ heterocyclic group are a pyridine group, apyrimidine group, a pyrazine group, a pyridazine group, a triazinegroup, a quinoline group, a benzoquinoline group, an isoquinoline group,a benzoisoquinoline group, a quinoxaline group, a benzoquinoxalinegroup, a quinazoline group, a benzoquinazoline group, a cinnoline group,a phenanthroline group, a phthalazine group, a naphthyridine group, apyrrole group, a thiophene group, a furan group, an indole group, abenzoindole group, a naphthon indole group, an isoindole group, a benzoisoindole group, a naphthon isoindole group, a benzosilole group, abenzothiophene group, a benzofuran group, a carbazole group, adibenzosilole group, a dibenzothiophene group, a dibenzofuran group, anazacarbazole group, an azafluorene group, an azadibenzosilole group, anazadibenzothiophene group, an azadibenzofuran group, a pyrazole group,an imidazole group, a triazole group, a tetrazole group, an oxazolegroup, an isooxazole group, a thiazole group, an isothiazole group, anoxadiazole group, a thiadiazole group, a benzopyrazole group, abenzimidazole group, a benzoxazole group, a benzothiazole group, abenzoxadiazole group, a benzothiadiazole group, an imidazopyridinegroup, an imidazopyrimidine group, an imidazotriazine group, animidazopyrazine group, an imidazopyridazine group, an indenocarbazolegroup, an indolocarbazole group, a benzofurocarbazole group, abenzothienocarbazole group, a benzosilolocarbazole group, abenzoindolocarbazole group, a benzocarbazole group, a benzonaphthofurangroup, a benzonaphthothiophene group, a benzonaphthosilole group, abenzofurodibenzofuran group, a benzofurodibenzothiophene group, and abenzothienodibenzothiophene group.

The substituent of the substituted C₅-C₆₀ carbocyclic group, thesubstituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkylenegroup, the substituted C₂-C₆₀ alkenylene group, the substituted C₃-C₁₀cycloalkylene group, the substituted C₁-C₁₀ heterocycloalkylene group,the substituted C₃-C₁₀ cycloalkenylene group, the substituted C₁-C₁₀heterocycloalkenylene group, the substituted C₆-C₆₀ arylene group, thesubstituted C₁-C₆₀ heteroarylene group, the substituted divalentnon-aromatic condensed polycyclic group, the substituted divalentnon-aromatic condensed heteropolycyclic group, the substituted C₁-C₃₀alkyl group, the substituted C₂-C₆₀ alkenyl group, the substitutedC₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, thesubstituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substitutedmonovalent non-aromatic condensed polycyclic group, and the substitutedmonovalent non-aromatic condensed heteropolycyclic group may be:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or anitro group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, ora C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),—S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,or a monovalent non-aromatic condensed heteropolycyclic group, eachunsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁),—S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂;

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂), or

any combination thereof.

Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃ and Q₃₁ to Q₃₃ used herein may eachindependently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, or a terphenyl group.

The term “Ph” as used herein refers to a phenyl group, the term “Me” asused herein refers to a methyl group, the term “Et” as used hereinrefers to an ethyl group, the term “ter-Bu” or “Bu^(t)” as used hereinrefers to a tert-butyl group, and the term “OMe” as used herein refersto a methoxy group.

The term “biphenyl group” as used herein refers to “a phenyl groupsubstituted with a phenyl group”. In other words, the “biphenyl group”is a substituted phenyl group having a C₆-C₆₀ aryl group as asubstituent.

The term “terphenyl group” as used herein refers to “a phenyl groupsubstituted with a biphenyl group”. In other words, the “terphenylgroup” is a phenyl group having, as a substituent, a C₆-C₆₀ aryl groupsubstituted with a C₆-C₆₀ aryl group.

* and *′ used herein, unless defined otherwise, each refer to a bindingsite to a neighboring atom in a corresponding formula.

Hereinafter, a compound according to embodiments and a light-emittingdevice according to embodiments will be described in detail withreference to Synthesis Examples and Examples. The wording “B was usedinstead of A” used in describing Synthesis Examples refers to when anidentical molar equivalent of B was used in place of A.

EXAMPLES Synthesis Example: Synthesis of Compounds BD1 to BD8

Synthesis of Intermediate 1-1

Intermediate 1-1 was synthesized using Intermediate 1-0,1,5-dibromo-2,4-diiodobenzene (CAS: 96843-23-1), CuI, K₃PO₄, and BPPO ina DMSO solvent at 160° C. Intermediate 1-1 was confirmed by LC-MS.

C12H4Br4I2O: M+1 733.55

Synthesis of Intermediate 1-2

Intermediate 1-1 was reacted with imidazole (CAS: 288-13-1) andpotassium carbonate to synthesize Intermediate 1-2. Intermediate 1-2 wasconfirmed by LC-MS.

C18H10Br4N4O: M+1 613.77

Synthesis of Intermediate 1-3

Intermediate 1-2 was reacted with iodide methane (CAS: 74-88-4) usingacetone as a solvent to synthesize 1-3. Intermediate 1-3 was confirmedby LC-MS.

C20H16Br4I2N4O: M+1 897.61

Synthesis of Intermediate 1-4

Intermediate 1-4 was synthesized using Intermediate 1-3,dichloro(1,5-cyclooctadiene)platinum(II), and sodium acetate at 160° C.in a dioxane solvent. Intermediate 1-4 was confirmed by LC-MS.

C20H12Br4N4OPt: M+1 834.78

Synthesis of Intermediate 1-5

Intermediate 1-4 was reacted with imidazole (CAS: 288-13-1) andpotassium carbonate to synthesize Intermediate 1-5. Intermediate 1-5 wasconfirmed by LC-MS.

C32H24N12OPt: M+1 787.22

Synthesis of Intermediate 1-6

Intermediate 1-5 was reacted with iodide methane (CAS: 74-88-4) usingacetone as a solvent to synthesize Intermediate 1-6. Intermediate 1-6was confirmed by LC-MS.

C36H36I4N12OPt: M+1 1354.91

Synthesis of Intermediate 1-7

Intermediate 1-7 was synthesized using Intermediate 1-6, rhodium(III)chloride, and sodium acetate at 160° C. in a dioxane solvent.Intermediate 1-7 was confirmed by LC-MS.

C51H38F4I2N15OPtRh: M+1 1504.01

Synthesis of Compound BD1

Compound BD1 was synthesized using Intermediate 1-7,bis(1,5-cyclooctadiene)diiridium(I) dichloride, and sodium acetate at160° C. in a dioxen solvent. Compound BD1 was confirmed by LC-MS.

C66H40F8IrN18OPtRh: M+1 1743.21

The intermediate synthesis method of Compound BD1 was equally applied tosynthesis of Compounds BD2 to BD8.

The compounds synthesized according to Synthesis Examples above wereidentified by ¹H NMR and MS/FAB, and results are shown in Table 1 below.

Even compounds other than the compounds shown in Table 1 may be easilyrecognized by those skilled in the art by referring to the abovesynthesis routes and source materials.

TABLE 1 MS/FAB Compound ¹H NMR (CDCI₃, 400 MHz) found calc. 1 3.63 (s,6H), 3.67 (s, 6H), 3.69 1743.19 1743.21 (s, 6H), 6.49-6.54 (m, 12H),7.54-7.59 (m, 10H) 2 3.63 (s, 6H), 3.65 (s, 6H), 3.67 1799.56 1799.47(s, 6H), 3.70 (s, 6H), 3.72 (s, 6H), 6.49-6.54 (m, 8H), 7.54-7.59 (m,10H) 3 3.63 (s, 6H), 3.66 (s, 6H), 3.68 1843.46 1843.48 (s, 6H),6.51-6.60 (m, 10H), 7.52-7.64 (m, 18H) 4 3.62 (s, 6H), 3.61 (s, 6H),3.65 1845.75 1845.21 (s, 6H), 6.54-6.67 (m, 10H), 7.50-7.66 (m, 16H) 53.61 (s, 6H), 3.65 (s, 6H), 3.70 1833.20 1833.24 (s, 6H), 6.50-6.54 (m,12H), 7.44-7.50 (m, 10H) 6 3.62 (s, 6H), 3.64 (s, 6H), 3.68 1799.971799.25 (s, 6H), 3.72 (s, 6H), 3.74 (s, 6H), 6.50-6.54 (m, 8H),7.50-7.59 (m ,10H) 7 3.60 (s, 6H), 3.65 (s, 6H), 3.67 1843.55 1843.48(s, 6H), 6.51-6.62 (m, 10H), 7.52-7.64 (m, 18H) 8 3.62 (s, 6H), 3.61 (s,6H), 3.64 1845.64 1845.46 (s, 6H), 6.50-6.61 (m, 10H), 7.50-7.69 (m,16H)

Manufacture of Light-Emitting Device Example 1

As an anode, a glass substrate with 15 Ωcm² (1,200 Å) ITO thereon, whichwas manufactured by Corning Inc., was cut to a size of 50 mm×50 mm×0.7mm, and the glass substrate was sonicated by using isopropyl alcohol andpure water for 5 minutes each, and ultraviolet (UV) light was irradiatedfor 30 minutes thereto and ozone was exposed thereto for cleaning. Theresultant glass substrate was loaded onto a vacuum deposition apparatus.

A known material Compound NPD was vacuum-deposited on the ITO glasssubstrate to form a hole injection layer having a thickness of 300 Å,and TCTA as a hole transport compound was vacuum-deposited on the holeinjection layer to form a hole transport layer having a thickness of 200Å.

mCP and Compound BD1 of the disclosure were co-deposited at a weightratio of 99:1 thereon to form an emission layer having a thickness of200 Å.

Subsequently, TSP01 as an electron transport compound wasvacuum-deposited thereon to form an electron transport layer having athickness of 200 Å.

LiF as a halogenated alkali metal was deposited thereon to form anelectron injection layer having a thickness of 10 Å, and Al (cathode)was vacuum-deposited thereon to a thickness of 3,000 Å, thereby formingan LiF/Al electrode, resulting in completing the manufacture of alight-emitting device.

Example 2

A light-emitting device was manufactured in the same manner as inExample 1, except that Compound BD2 was used instead of Compound BD1 informing an emission layer.

Example 3

A light-emitting device was manufactured in the same manner as inExample 1, except that Compound BD3 was used instead of Compound BD1 informing an emission layer.

Example 4

A light-emitting device was manufactured in the same manner as inExample 1, except that Compound BD4 was used instead of Compound BD1 informing an emission layer.

Example 5

A light-emitting device was manufactured in the same manner as inExample 1, except that Compound BD5 was used instead of Compound BD1 informing an emission layer.

Example 6

A light-emitting device was manufactured in the same manner as inExample 1, except that Compound BD6 was used instead of Compound BD1 informing an emission layer.

Example 7

A light-emitting device was manufactured in the same manner as inExample 1, except that Compound BD7 was used instead of Compound BD1 informing an emission layer.

Example 8

A light-emitting device was manufactured in the same manner as inExample 1, except that Compound BD8 was used instead of Compound BD1 informing an emission layer.

Comparative Example 1

A light-emitting device was manufactured in the same manner as inExample 1, except that known Compound A was used instead of Compound BD1in forming an emission layer.

A Comparative Example 2

A light-emitting device was manufactured in the same manner as inExample 1, except that known Compound B was used instead of Compound BD1in forming an emission layer.

B

In order to evaluate characteristics of the light-emitting devicesmanufactured in Examples 1 to 8 and Comparative Examples 1 and 2,driving voltage and efficiency were measured in a current density of 10mA/cm².

The driving voltage and current density of the light-emitting deviceswere measured by using a source meter (Keithley Instrument, 2400series).

TABLE 2 Half-life Dopant in Driving Current span (hr emission voltagedensity Luminance Efficiency Emission @100 layer (V) (mA/cm²) (cd/m²)(cd/A) color mA/cm²) Example 1 Compound 4.3 6.5 1000 33.40 Blue 3.7 BD1color Example 2 Compound 4.5 6.1 1000 32.43 Blue 3.7 BD2 color Example 3Compound 4.4 6.5 1000 28.68 Blue 3.2 BD3 color Example 4 Compound 5.36.5 1000 22.17 Blue 3.5 BD4 color Example 5 Compound 5.5 6.1 1000 31.33Blue 3.2 BD5 color Example 6 Compound 4.6 6.2 1000 29.30 Blue 3.4 BD6color Example 7 Compound 5.3 6.2 1000 30.27 Blue 3.3 BD7 color Example 8Compound 4.7 6.4 1000 30.11 Blue 2.9 BD8 color Comparative Compound A5.3 6.0 1000 25.95 Blue 1.5 Example 1 color Comparative Compound B 5.55.2 1000 24.47 Blue 0.2 Example 2 color

Referring to Table 2, it was confirmed that the light-emitting devicesmanufactured according to Examples 1 to 8 showed excellent resultscompared to those of the light-emitting devices manufactured accordingto Comparative Examples 1 and 2.

When the trimetallic complex of Formula 1 according to an embodiment isused as a material of emission layer, driving voltage may decrease andefficiency and lifespan may increase, compared to known compounds.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments. While embodiments have been describedwith reference to the FIGURE, it will be understood by those of ordinaryskill in the art that various changes in form and details may be madetherein without departing from the spirit and scope as defined by thefollowing claims.

What is claimed is:
 1. A trimetallic complex represented by Formula 1:

wherein in Formula 1, M₁, M₂, and M₃ are transition metals, A₁ to A₆ andB₁ to B₆ are each independently selected from a C₅-C₆₀ carbocyclic groupand a C₁-C₆₀ heterocyclic group, Y₁ to Y₂₆ are each independently C orN, X₁₁ to X₁₆ and X₂₁ to X₂₆ are each independently C or N, L isselected from a single bond, *—O—*′, *—S—′, *—C(R₂₁)(R₂₂)—*′,*—C(R₂₁)═*′, *═C(R₂₁)—*′, *—C(R₂₁)═C(R₂₂)—*′, *—C(═O)—*′, *—C(═S)—*′,*—C≡C—*′, *—B(R₂₁)—*′, *—N(R₂₁)—*′, *—P(R₂₁)—*′, *—Si(R₂₁)(R₂₂)—*′,*—P(R₂₁)(R₂₂)—*′, and *—Ge(R₂₁)(R₂₂)—*′, R₁ to R₁₂, R₂₁, and R₂₂ areeach independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted heterocycloalkyl group,a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substitutedor unsubstituted heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂),—P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and—P(═S)(Q₁)(Q₂), two adjacent substituents selected from the groupconsisting of R₁ to R₁₂, R₂₁, and R₂₂ are optionally linked to eachother to form a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group, a1 to a12 areeach independently an integer from 1 to 4, * and *′ each indicate abinding site to a neighboring atom, and at least one substituent of thesubstituted C₅-C₆₀ carbocyclic group, the substituted C₁-C₆₀heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substitutedC₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, thesubstituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkylgroup, the substituted C₁-C₁₀ heterocycloalkyl group, the substitutedC₃-C₁₀ cycloalkenyl group, the substituted heterocycloalkenyl group, thesubstituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, thesubstituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroarylgroup, the substituted monovalent non-aromatic condensed polycyclicgroup, and the substituted monovalent non-aromatic condensedheteropolycyclic group is selected from: deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, anda C₁-C₆₀ alkoxy group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, a hydroxyl group, a cyano group, a nitro group,an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃),—N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and—P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclicgroup, and a monovalent non-aromatic condensed heteropolycyclic group; aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group,a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),—B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ toQ₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroarylgroup, a monovalent non-aromatic condensed polycyclic group, amonovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group.
 2. The trimetallic complex of claim 1,wherein M₁, M₂, and M₃ are each independently selected from platinum(Pt), palladium (Pd), copper (Cu), silver (Ag), gold (Au), rhodium (Rh),iridium (Ir), ruthenium (Ru), and osmium (Os).
 3. The trimetalliccomplex of claim 1, wherein M₁ is selected from platinum (Pt), palladium(Pd), and osmium (Os).
 4. The trimetallic complex of claim 1, wherein M₂and M₃ are each independently selected from rhodium (Rh), iridium (Ir),and ruthenium (Ru).
 5. The trimetallic complex of claim 1, wherein A₁ toA₆ and B₁ to B₆ are each independently selected from a benzene group, anaphthalene group, an anthracene group, a phenanthrene group, an azulenegroup, a triphenylene group, a pyrene group, a chrysene group, acyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a furangroup, a thiophene group, a silole group, an indene group, a fluorenegroup, an indole group, a carbazole group, a benzofuran group, adibenzofuran group, a benzothiophene group, a dibenzothiophene group, abenzosilole group, a dibenzosilole group, an indenopyridine group, anindolopyridine group, a benzofuropyridine group, a benzothienopyridinegroup, a benzosilolopyridine group, an indenopyrimidine group, anindolopyrimidine group, a benzofuropyrimidine group, abenzothienopyrimidine group, a benzosilolopyrimidine group, adihydropyridine group, a pyridine group, a pyrimidine group, a pyrazinegroup, a pyridazine group, a triazine group, a quinoline group, anisoquinoline group, a quinoxaline group, a quinazoline group, aphenanthroline group, a pyrrole group, a pyrazole group, an imidazolegroup, a 2,3-dihydroimidazole group, a triazole group, a2,3-dihydrotriazole group, an oxazole group, an isooxazole group, athiazole group, an isothiazole group, an oxadiazole group, a thiadiazolegroup, a benzopyrazole group, a pyrazolopyridine group, a furopyrazolegroup, a thienopyrazole group, a benzimidazole group, a2,3-dihydrobenzimidazole group, an imidazopyridine group, a2,3-dihydroimidazopyridine group, a furo imidazole group, athienoimidazole group, an imidazopyrimidine group, a2,3-dihydroimidazopyrimidine group, an imidazopyrazine group, a2,3-dihydroimidazopyrazine group, a benzoxazole group, a benzothiazolegroup, a benzoxadiazole group, a benzothiadiazole group, a5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinolinegroup.
 6. The trimetallic complex of claim 1, wherein Y₄, Y₉, Y₁₀, Y₁₅,Y₂₀, Y₂₁, Y₂₄, and Y₂₅ are each N.
 7. The trimetallic complex of claim1, wherein X₁₁ to X₁₆ and X₂₁ to X₂₆ are each C.
 8. The trimetalliccomplex of claim 1, wherein L is *—O—*′, and Y₁, Y₇, Y₈, Y₁₁, Y₁₂, Y₁₈,Y₁₉, Y₂₂, Y₂₃, Y₂₆, X₁₁, X₁₄, X₂₁, and X₂₄ are each C.
 9. Thetrimetallic complex of claim 1, wherein A₁ to A₆ and B₁ to B₆ are eachindependently selected from a C₅-C₆ carbocyclic group and a C₃-C₇heterocyclic group.
 10. The trimetallic complex of claim 1, wherein A₁to A₆ are each independently a C₅ heterocyclic group.
 11. Thetrimetallic complex of claim 1, wherein B₁ to B₆ are each independentlya C₃-C₇ heterocyclic group.
 12. The trimetallic complex of claim 1,wherein A₁ to A₆ are each independently a 6-membered ring comprising oneor more N(s).
 13. The trimetallic complex of claim 1, wherein B₁ to B₆are each independently a 5-membered ring comprising two or more N(s).14. The trimetallic complex of claim 1, wherein A₁ to A₆ and B₁ to B₆are each independently selected from a benzene group, a pyridine group,an imidazole group, a 2,3-dihydroimidazole group, an imidazopyrimidinegroup, and a benzimidazole group.
 15. The trimetallic complex of claim1, wherein Formula 1 is a trimetallic complex represented by Formula 2below:

wherein in Formula 2, M₁, M₂, and M₃ are the same as described inconnection with Formula 1, L is the same as described in connection withFormula 1, R₁ to R₁₂ are the same as described in connection withFormula 1, a1 to a12 are the same as described in connection withFormula 1, R₃₁ to R₃₆ are the same as described in connection with R₁ ofFormula 1, and X₃₁ to X₃₄ each independently indicate C or N.
 16. Thetrimetallic complex of claim 15, wherein L is *—O—*′, R₁ to R₁₂ are eachindependently —F, —Cl, —Br, or —I, and R₃₁ to R₃₆ are each independentlya substituted or unsubstituted C₁-C₆₀ alkyl group.
 17. The trimetalliccomplex of claim 1, wherein the trimetallic complex represented byFormula 1 is any one of the following compounds:


18. A light-emitting device comprising: a first electrode; a secondelectrode facing the first electrode; and a middle layer disposedbetween the first electrode and the second electrode and comprising anemission layer, wherein the middle layer comprises the trimetalliccomplex of claim
 1. 19. The light-emitting device of claim 18, whereinthe first electrode is an anode, the second electrode is a cathode, andthe middle layer comprises: a hole transport region disposed between thefirst electrode and the emission layer and comprising at least oneselected from the group consisting of a hole injection layer, a holetransport layer, an emission auxiliary layer, and an electron blockinglayer; and an electron transport region disposed between the emissionlayer and the second electrode and comprising at least one selected formthe group consisting of a hole blocking layer, an electron transportlayer, and an electron injection layer.
 20. An electronic apparatuscomprising a thin-film transistor and the light-emitting device of claim18, wherein the thin-film transistor comprises: a source electrode; adrain electrode; an activation layer; and a gate electrode, and thefirst electrode of the light-emitting device is electrically connectedto one of the source electrode and the drain electrode of the thin-filmtransistor.